Field of the Invention
The present invention relates to a novel fusion protein comprising the transcription modulation domain (TMD) of the transcription factor NF-κB subunit p65 and a protein transduction domain (PTD) and to the use thereof.
Description of the Related Art
Cytokines that are regulated by the transcription factor NF-κB include tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1), interleukin-6 and granulocyte-macrophage colony stimulating factor (GM-CSF), and chemokines that are regulated by NF-κB include interleukin-8, macrophage-inflammatory protein-1α (MIP-1α), methyl accepting chemotaxis protein-1 (MCP-1) and eotaxin. In addition, adhesion molecules that are regulated by NF-κB include E-selectin, vascular cell adhesion molecule-1 (VCAM-1), endothelial leukocyte adhesion molecule-1 (ELAM-1) and intercellular cell adhesion molecule-1 (ICAM-1), and inducible enzymes that are regulated by NF-κB include cyclooxygenase-2 (COX-2) and the like. Thus, NF-κB is involved in almost all physiological reactions in the body.
The transcription factor NF-κB is composed of different subunits composed of homodimers or heterodimers. NF-κB proteins include RelA (p65), c-Rel, Rel-B, NF-κB1 (p50) and NF-κB2 (p52), and p50 and p52 are produced from NF-κB1 (p105) and NF-032 (p100), respectively, which are their precursors. The NF-κB proteins each contains about 300 amino acids, called the N-terminal Rel-homology domain (RHD), which is involved in dimerization, binding to specific DNA and reactions with IκB protein. Furthermore, these proteins also contain a nuclear localization signal (NLS) that enables the proteins to act as transcription factors by localization to the nucleus. In addition, the NF-κB proteins may be classified, according to the presence or absence of the C-terminal transactivation domain (TAD), into class I (NF-κB1 and NF-κB) and class II (RelA/p65, RelB, and c-Rel). Class II has a transactivation domain that enables the NF-κB proteins to act as transcription factors without needing other NF-κB domains, and class I has no transactivation domain. Dimers are formed between the NF-κB proteins of the two classes to act as DNA transcription factors. Among the dimers, a p50/p65 dimer is most frequently present. RelA(p65), RelB and c-Rel have a C-terminal transactivation domain, and thus can activate the expression of their target genes. On the contrary, p50 and p52, which are NF-κB1 and NF-κB2, respectively, have no C-terminal transactivation domain, and thus homodimers of p50 and p52 do not act as transcription factors if they do not have bound thereto proteins such as co-activators having a transactivation domain.
A protein transduction domain (PTD) is a short peptide having strong hydrophobicity, and is known to effectively transduce physiologically active molecules such as proteins, DNA and RNA, fused therewith, into cells. The present inventors have developed two PTDs to date, and the PTDs are disclosed in detail in WO 2003059940 and WO 2003059941. Because the protein transduction domain can transduce a physiologically active molecule not only into the cytoplasm but also into the nucleus, it has a property suitable for transducing a modified transcription factor, which is the key substance of the present invention, into the nucleus.
Therefore, the present inventors have attempted to use a fusion protein comprising the transduction modulation domain of the NF-κB subunit p65 and a protein transduction domain to inhibit the transcription and activity of NF-κB by competitive inhibition to thereby treat effectively a disease caused by NF-κB overactivity.
Throughout the specification, a number of publications and patent documents are referred to and cited. The disclosure of the cited publications and patent documents is incorporated herein by reference in its entirety to more clearly describe the state of the related art and the present invention.